Methods and materials for anchoring gapfill metals

ABSTRACT

One aspect of the present invention includes a method of fabricating an electronic device. According to one embodiment, the method comprises providing a substrate having dielectric oxide surface areas adjacent to electrically conductive surface areas, chemically bonding an anchor compound with the dielectric oxide surface areas so as to form an anchor layer, initiating the growth of a metal using the electrically conductive surface areas and growing the metal so that the anchor layer also bonds with the metal. The anchor compound has at least one functional group capable of forming a chemical bond with the oxide surface and has at least one functional group capable of forming a chemical bond with the metal. Another aspect of the present invention is an electronic device. A third aspect of the present invention is a solution comprising the anchor compound.

CROSS REFERENCES

This application is related to U.S. patent application Ser. No.12/334,460, titled “ACTIVATION SOLUTION FOR ELECTROLESS PLATING ONDIELECTRIC LAYERS” to Artur KOLICS, filed Dec. 21, 2007 which isincorporated herein, in its entirety, by this reference.

BACKGROUND

This invention pertains to fabrication of electronic devices such asintegrated circuits; more specifically, this invention relates tomethods and compositions to improve the adhesion between gapfill metalsand dielectrics for electronic devices.

Electroless deposition is a process that is frequently used in thefabrication of electronic devices. The process is particularly importantfor applications requiring deposition of metal layers such as gapfillmetal on substrates comprising metal surface areas and dielectricsurface areas such as structures for damascene and/or dual damascenedevices. These processes are also in use for applications such asforming electrical connections to metal contacts for integratedcircuits. Electroless deposition processes can readily proceed oncertain catalytic or activated surfaces. The adhesion to the catalyticor activated surfaces may be satisfactory. Similarly, chemical vapordeposition processes used for depositing metals on the metal surfacesmay also have satisfactory adhesion. However, metals deposited byelectroless deposition and metals deposited by chemical vapor depositionmay have poor adhesion to dielectric surfaces. Consequently, thedeposited metals may be attached or held only by the metal surface areasof the substrate. Such surfaces may provide only a small portion of thecontact surface area in comparison to contact with the dielectricsurfaces and the overall adhesion of the metal to the substrate may beinsufficient for subsequent processes.

There is a need for methods and materials for improving the adhesion ofmetal such as gapfill metal to dielectric surfaces for the fabricationof a variety of electronic devices.

SUMMARY

This invention pertains to electronic devices, more particularly, tometallization of electronic devices. The present invention provides oneor more improvements in the solutions used for and methods offabricating electronic devices such as for fabricating semiconductordevices that include integrated circuits.

One aspect of the present invention includes a method of fabricating anelectronic device. According to one embodiment, the method comprisesproviding a substrate having dielectric oxide surface areas adjacent toelectrically conductive surface areas, chemically bonding an anchorcompound with the dielectric oxide surface areas so as to form an anchorlayer, initiating the growth of a metal using the electricallyconductive surface areas, and growing the metal so that the anchor layeralso bonds with the metal. The anchor compound has at least onefunctional group capable of forming a chemical bond with the dielectricoxide surface and has at least one functional group capable of forming achemical bond with the metal. Another aspect of the present invention isan electronic device. A third aspect of the present invention is asolution comprising the anchor compound.

It is to be understood that the invention is not limited in itsapplication to the details of construction and to the arrangements ofthe components set forth in the following description or illustrated inthe drawings. The invention is capable of other embodiments and of beingpracticed and carried out in various ways. In addition, it is to beunderstood that the phraseology and terminology employed herein are forthe purpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conceptionupon which this disclosure is based may readily be utilized as a basisfor the designing of other structures, methods, and systems for carryingout aspects of the present invention. It is important, therefore, thatthe claims be regarded as including such equivalent constructionsinsofar as they do not depart from the spirit and scope of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section side view diagram of a substrate beingprocessed according to an embodiment of the present invention.

FIG. 2 is a cross-section side view diagram of a substrate beingprocessed according to an embodiment of the present invention.

FIG. 3 is a cross-section side view diagram of a substrate processedaccording to an embodiment of the present invention.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the figures maybe exaggerated relative to other elements to help to improveunderstanding of embodiments of the present invention.

DESCRIPTION

This invention pertains to electronic devices, more particularly, tometallization of electronic devices. The present invention seeks toovercome one or more problems in fabricating electronic devices such asfor fabricating semiconductor devices that use integrated circuits.

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification. All numeric values are herein defined as beingmodified by the term “about,” whether or not explicitly indicated. Theterm “about” generally refers to a range of numbers that a person ofordinary skill in the art would consider equivalent to the stated valueto produce substantially the same properties, function, result, etc. Anumerical range indicated by a low value and a high value is defined toinclude all numbers subsumed within the numerical range and allsubranges subsumed within the numerical range. As an example, the range10 to 15 includes, but is not limited to, 10, 10.1, 10.47, 11, 11.75 to12.2, 12.5, 13 to 13.8, 14, 14.025, and 15.

The term “metal” is used herein to refer to a metal element in theperiodic table of the elements and/or to metal alloys comprising one ormore metal elements mixed with at least one other element; the metal andthe metal alloys have the general properties of metal elements from theperiodic table of the elements such as high electrical conductivity.

The term “valence” of a chemical element is defined here as the maximumnumber of univalent atoms that may combine with an atom of the elementunder consideration, or with a fragment, or for which an atom of thiselement can be substituted in accordance with the International Union ofPure and Applied Chemist Compendium of Chemical Terminology, 2nd Edition(1997).

The term “anchor compound” is used herein to refer to a molecule or ionhaving one or more functional groups that form a chemical bond with anoxide surface and one or more functional groups that form a chemicalbond with a metal or metal alloy having properties suitable for use asgapfill metal in an electronic device.

Embodiments of and the operation of embodiments of the present inventionwill be discussed below primarily in the context of processingsemiconductor wafers such as silicon wafers used for fabricatingintegrated circuits. The following discussion is primarily directedtowards silicon electronic devices that use metallization layers havingmetal layers formed on or in oxide dielectric structures such as metallayers used for fabricating gate contacts. However, it is to beunderstood that embodiments in accordance with the present invention maybe used for other semiconductor devices, a variety of metal layers, andsemiconductor wafers other than silicon.

In the following description of the figures, identical referencenumerals have been used when designating substantially identicalelements or processes that are common to the figures.

One aspect of the present invention includes a method of fabricating anelectronic device. Reference is now made to FIG. 1, FIG. 2, and FIG. 3,where there is shown a cross-section side view of a substrate beingprocessed by methods according to one or more embodiments of the presentinvention. According to one embodiment of the present invention, themethod comprises providing a substrate 101. As shown in FIG. 1,substrate 101 includes a base 110 and a dielectric oxide 115 on base110. Dielectric oxide 115 has one or more vias and/or one or moretrenches 120 formed therein. The one or more vias and/or one or moretrenches 120 expose electrically conductive areas such as metal contact130. Areas of dielectric oxide 115 are adjacent to the electricallyconductive areas such as metal contact 130. Metal contact 130 may beessentially the same as metal contacts such as those for semiconductorcircuits. As an option for one or more embodiments of the presentinvention, the electrically conductive areas may be a silicide such as,but not limited to, nickel platinum silicide for a semiconductor circuitcontact.

The method further comprises chemically bonding an anchor compound withthe dielectric oxide surface areas to form an anchor layer 135 asillustrated in FIG. 2. In general, the anchor compound has at least onefunctional group capable of forming a chemical bond with the oxidesurface and has at least one functional group capable of forming achemical bond with a gapfill metal. The anchor compound has suitableproperties and is applied under conditions so that the anchor compoundsubstantially only forms a bond with the dielectric oxide to form anchorlayer 135 on dielectric 115 substantially without forming a bond withmetal contact 130. Consequently, anchor layer 135 is present ondielectric 115, but is not present on metal contact 130. Anchor layer135 comprises a chemical reaction product from a reaction of dielectricoxide layer 115 with the anchor compound.

The method further comprises initiating the growth of a metal using theelectrically conductive surface area shown as metal contact 130 andgrowing the metal to fill the one or more trenches and/or one or morevias with a gapfill metal 140 so that the anchor compound also bondswith the metal contacting the dielectric oxide surface areas.

In one or more embodiments of the method of fabricating electronicdevices, gapfill metal 140 is selectively deposited. Optionally, gapfillmetal 140 may be selectively deposited by a process such as electrolessdeposition or gapfill metal 140 may be selectively deposited by aprocess such as chemical vapor deposition. More specifically, thegapfill metal growth is started at a metal contact such as metal contact130 at the bottom of a via or the bottom of a trench that has beenformed in dielectric 115. The gapfill metal growth is continued so as toachieve a bottom-up fill of the via and/or the trench.

According to one or more embodiments of the present invention,electroless deposition of gapfill metal 140 is accomplished by placingthe substrate with anchor layer 135 into an electroless depositionsolution. The electroless deposition solution is formulated so as toform a metal, metal alloy, or metal composite layer. Descriptions ofelectroless deposition processes suitable for one or more embodiments ofthe present invention can be found in U.S. Pat. No. 6,794,288 to Kolicset al. and U.S. Pat. No. 6,911,076 to Kolics et al.; the contents of allof these patents are incorporated herein, in their entirety by thisreference.

It should be noted that the diagrams in FIG. 1, FIG. 2, and FIG. 3 arenot drawn to scale. More specifically, the thickness of anchor layer 120is exaggerated for the purpose of illustration. Furthermore, the diagramin FIG. 3 shows electronic device 103 having metal layer 140 as agapfill metal. Still further, the diagram shown in FIG. 3 presents aplanarized surface so as to form a damascene metallization structure.

According to one or more embodiments of the present invention, themethod includes using an anchor compound that comprises an inorganicoxoanion, an amine, an imine, a cyanide, or combinations thereof. One ormore other embodiments of the present invention use anchor compoundshaving functional groups that can form complexes with ions of the metalused for the gapfill and/or functional groups that adsorb strongly onthe gapfill metal. Embodiments of the present invention that use cobaltin the gapfill metal comprise using anchor compounds having functionalgroups that can form complexes with ions of cobalt and/or functionalgroups that adsorb strongly on cobalt.

According to one or more embodiments of the present invention, themethod includes using an anchor compound that comprises an inorganicoxoanion having the general formula A_(X)O_(Y) ^(Z−) wherein, A is achemical element, O is oxygen, X is an integer, Y is an integer, and Zis an integer. Some examples of inorganic oxoanions for one or moreembodiments of the present invention include, but are not limited to,phosphates and phosphites.

According to one or more embodiments of the present invention, themethod includes using an anchor compound having the general formula:

(R₁—O)_(V−n)MG_(n) where

-   -   M is germanium, hafnium, indium, silicon, tantalum, tin,        titanium, or tungsten;    -   G is a functional group capable of forming a chemical bond with        the metal;    -   R₁—O is a functional group capable of forming a chemical bond        with the oxide surface, O is oxygen;    -   V is the valence of M; and    -   n is an integer from 1 to V−1.        According to one embodiment of the present invention, R₁ is an        alkyl group, M is silicon, and G is an alkylamine.

One or more embodiments of the present invention include using anchorcompounds of the formula presented above wherein G_(n) comprises groupssuch as, but not limited to, amine, imine, epoxy, hydroxyl, carboxy,carboxylate, phosphate, phosphonate, or combinations thereof.Optionally, one or more embodiments of the present invention includeusing anchor compounds wherein G_(n) comprises, sulfonate, boronate,carbonate, bicarbonate, or combinations thereof. One or more embodimentsof the present invention include using anchor compounds wherein(R₁—O)_(V−n) comprises methoxy, ethoxy, propoxy, or combinationsthereof. One or more embodiments of the present invention include usinganchor compounds wherein (R₁—O)_(V−n) comprises methoxy, ethoxy,propoxy, or combinations thereof and G comprises amine, imine, epoxy,hydroxyl, carboxy, carboxylate, phosphate, phosphonate, or combinationsthereof.

According to one or more embodiments of the present invention, themethod includes using an anchor compound that comprises mono-alkoxysilane or di-alkoxy silane and at least one from the group consisting ofan amine group, an imine group, a carboxylate group, a cyanide group, aphosphate group, a phosphite group, a phosphonate group, and an epoxygroup.

According to one or more embodiments of the present invention, themethod further comprises making the surface of metallization contactssuch as metal contact 130 substantially oxide free prior to thechemically bonding an anchor compound with dielectric oxide 115. Thisadditional process is optional and may only be used for metallizationcontacts that are susceptible to oxide formation. The oxide is removedfrom the metallization contact so that the subsequent process of bondingthe anchor compound to the dielectric oxide does not bond the anchorcompound to oxide formed on the metallization contact.

Methods according to one or more embodiments of the present inventionmay also include a thermal process to more completely bond the anchorlayer to the dielectric. The thermal process may include heating thesubstrate during and/or after exposing the substrate to the anchorcompound. According to one or more embodiments of the present inventionthe thermal process is performed prior to beginning the growth of thegapfill metal.

According to one or more embodiments of the present invention, examplesof dielectric oxides suitable for use as dielectric oxide 115 include,but are not limited to, aluminum oxide (Al₂O₃), silicon dioxide (SiO₂),carbon doped silicon dioxide (SiOC), silicon oxide-based low kdielectrics, and silicon oxides such as SiOCH, SiON, SiOCN, and SiOCHN.Alternative oxides for embodiments of the present invention include, butare not limited to, tantalum pentoxide (Ta₂O₅) and titanium dioxide(TiO₂). Optionally, the dielectric oxide, according to one or moreembodiments of the present invention, may be a surface oxide formed on adissimilar material such as silicon oxide formed on materials such as,but not limited to, aluminum nitride, silicon nitride, siliconcarbonitride, and silicon carbide.

One or more embodiments of the present invention may include using avariety of gapfill metals. Examples of gapfill metals suitable for oneor more embodiments of the present invention include, but are notlimited to, metals comprising cobalt, copper, gold, iridium, nickel,osmium, palladium, platinum, rhenium, ruthenium, rhodium, silver, tin,zinc, electrolessly plated alloys, or mixtures thereof. According to oneembodiment of the present invention, the gapfill metal comprises cobalt.According to another embodiment of the present invention, the gapfillmetal comprises cobalt and the metal contact comprises nickel platinumsilicide. According to another embodiment of the present invention, thegapfill metal comprises cobalt, the metal contact comprises nickelplatinum silicide, and the anchor compound comprises an oxoanion.

A variety of compounds can be used for anchor compounds according to oneor more embodiments of the present invention. According to oneembodiment of the present invention, the anchor compounds are applied tothe substrates as liquids or as components of liquid solutions using wetchemical processes. According to one or more embodiments of the presentinvention, the anchor compounds are dissolved in liquids such as, butnot limited to, water, water-soluble solvents, dimethylsulfoxide,formamide, acetonitrile, alcohol, or mixtures thereof. Otherwater-soluble solvents suitable for embodiments of the present inventionwill be clear to persons of ordinary skill in the art, in view of thepresent disclosure. According to another embodiment of the presentinvention, the anchor compounds are applied to the substrates as a gasor vapor using dry chemical processing or using substantially drychemical processes. More specifically, according to one or moreembodiments of the present invention, the anchor compound is applied tothe substrates as a gas under conditions so that the anchor compoundbonds to the dielectric oxide of the substrates. Optionally, the gasphase anchor compound may be mixed with another gas such as, but notlimited to, a substantially inert carrier gas.

In another embodiment of the present invention, anchor layer 135 isformed by immersing the substrate in the anchor compound or in asolution containing the anchor compound to bond the anchor compound tothe oxide surface for a time from about 30 seconds to about 600 secondsat a temperature from about 10° C. to about 95° C. According to anotherembodiment, the substrate is immersed in a solution containing theanchor compound to bond the anchor compound to the oxide surface fromabout 60 seconds to about 180 seconds at a temperature from about 50° C.to about 70° C.

According to one or more embodiments of the present invention, themethod comprises providing a substrate having metallization contacts anddielectric oxide. The dielectric oxide has vias to the metallizationcontacts. The method includes bonding an anchor compound with thedielectric oxide by exposing the dielectric oxide to the anchor compoundand/or to a solution containing the anchor compound so as to form ananchor layer on the dielectric oxide. The method further includesinitiating the selective growth of a gapfill metal using themetallization contacts. Optionally, the selective growth of the gapfillmetal may be accomplished using processes such as, but not limited to,atomic layer deposition, chemical vapor deposition, and electrolessdeposition. The gapfill metal is grown so that the anchor layer formedby the anchor compound bonding with the dielectric oxide also bonds withthe gapfill metal that is adjacent to or contacts the dielectric oxide.The anchor compound and the resulting anchor layer are selected so thatthey do not significantly cause growth of the gapfill metal. Morespecifically, the growth of the gapfill metal is the result of growthinitiated by the metal contact at the bottom of the trench and/or via.The growth of the metal gapfill is continued so that the vias and/ortrenches are at least filled with the gapfill metal. A planarizationprocess may be used after completion of the gapfill. According to one ormore embodiments of the present invention, the gapfill metal is a metalcomprising cobalt or a cobalt alloy.

Another aspect of the present invention comprises an electronic devicesuch as, but not limited to, an integrated circuit. Reference is againmade to FIG. 3. According to one embodiment of the present invention,the electronic device comprises a base 110 such as a semiconductorwafer, a metallization contact 130, a dielectric oxide 115 having a via120 to the metallization contact 130, a gapfill metal 140 grown frommetallization contact 130 substantially filling via 120, and an anchorlayer 135 chemically bonded between the surface of dielectric oxide 115and gapfill metal 140. The electronic device has substantially none ofthe anchor layer between the interface at metallization contact 130 andgapfill metal 140.

According to one or more embodiments of the present invention, theanchor layer is a chemical reaction product from a reaction of the oxidesurface and a reaction of the gapfill metal with an anchor compoundhaving the general formula:

(R₁—O)_(V−n)MG_(n) where

-   -   M is germanium, hafnium, indium, silicon, tantalum, tin,        titanium, or tungsten;    -   G is a functional group capable of forming a chemical bond with        the metal;    -   R₁—O is a functional group capable of forming a chemical bond        with the oxide surface, O is oxygen;    -   V is the valence of M; and    -   n is an integer from 1 to V−1.        According to one embodiment of the present invention, R₁ is an        alkyl group, M is silicon, and G is an alkylamine. As an option        for one or more embodiments of the present invention, G        comprises amine, imine, epoxy, hydroxyl, carboxy, carboxylate,        phosphate, phosphonate, or combinations thereof. As an option        for one or more embodiments of the present invention, R₁— is an        alkyl group.

According to one or more embodiments of the present invention, theanchor compound comprises mono-alkoxy silane or di-alkoxy silane and atleast one from the group consisting of an amine group, an imine group, acarboxylate group, a cyanide group, a phosphate group, a phosphitegroup, a phosphonate group, and an epoxy group.

According to one or more embodiments of the present invention, theanchor compounds have the formula presented above wherein G_(n)comprises groups such as, but not limited to, amine, imine, epoxy,hydroxyl, carboxy, carboxylate, phosphate, phosphonate, or combinationsthereof. According to one or more embodiments of the present invention,the anchor compounds have the formula presented above wherein G_(n)comprises, sulfonate, boronate, carbonate, bicarbonate, or combinationsthereof.

According to one or more embodiments of the present invention, theanchor compounds have the formula presented above wherein (R₁—O)_(V−n)comprises methoxy, ethoxy, propoxy, or combinations thereof. Accordingto one or more embodiments of the present invention, the anchorcompounds have the formula presented above wherein (R₁—O)_(4−n)comprises methoxy, ethoxy, propoxy, or combinations thereof and Gcomprises amine, imine, epoxy, hydroxyl, carboxy, carboxylate,phosphate, phosphonate, or combinations thereof.

According to one or more embodiments of the present invention, theanchor layer is a chemical reaction product from a reaction of the oxidesurface and a reaction of the gapfill metal with an anchor compound thatcomprises an inorganic oxoanion, an amine, an imine, a cyanide, orcombinations thereof. One or more other embodiments of the presentinvention use anchor compounds having functional groups that can formcomplexes with ions of the metal used for the gapfill and/or functionalgroups that adsorb strongly on the gapfill metal. Embodiments of thepresent invention that use cobalt in the gapfill metal comprise usinganchor compounds having functional groups that can form complexes withions of cobalt and/or functional groups that adsorb strongly on cobalt.

According to one or more embodiments of the present invention, theanchor layer is a chemical reaction product from a reaction of the oxidesurface and a reaction of the gapfill metal with an anchor compound thatcomprises an inorganic oxoanion having the generic formula A_(X)O_(Y)^(Z−) wherein, A is a chemical element, O is oxygen, X is an integer, Yis an integer, and Z is an integer. Some examples of inorganic oxoanionsfor one or more embodiments of the present invention include, but arenot limited, phosphates and phosphites.

According to one or more embodiments of the present invention thedielectric oxide such as dielectric oxide 115 comprises oxides such as,but not limited to, aluminum oxide (Al₂O₃), silicon dioxide (SiO₂),carbon doped silicon dioxide (SiOC), silicon oxide-based low kdielectrics, and silicon oxides such as SiOCH, SiON, SiOCN, and SiOCHN.Alternative oxides for embodiments of the present invention include butare not limited to tantalum pentoxide (Ta₂O₅) and titanium dioxide(TiO₂). Optionally, the dielectric oxide, according to one or moreembodiments of the present invention, may be a surface oxide formed on adissimilar material such as oxide formed on materials such as, but notlimited to, aluminum nitride, silicon nitride, silicon carbonitride, andsilicon carbide.

One or more embodiments of the present invention may include using avariety of gapfill metals. Examples of gapfill metals suitable for oneor more embodiments of the present invention include, but are notlimited to, metals comprising cobalt, copper, gold, iridium, nickel,osmium, palladium, platinum, rhenium, ruthenium, rhodium, silver, tin,zinc, electrolessly plated alloys, or mixtures thereof. According to oneembodiment of the present invention the gapfill metal comprises cobalt.According to another embodiment of the present invention the gapfillmetal comprises cobalt and the metal contact comprises nickel platinumsilicide. According to another embodiment of the present inventiongapfill metal comprises cobalt, the metal contact comprises nickelplatinum silicide, and the anchor compound comprises an oxoanion.

According to one or more embodiments of the present invention, themethod of making electronic devices described above and the electronicdevices described above include using a liquid solution to bond ananchor compound to an oxide dielectric to form an anchor layer. Theanchor compound has at least one functional group capable of forming achemical bond with the oxide surface and has at least one functionalgroup capable of forming a chemical bond with the metal.

According to one or more embodiments of the present invention, thesolution comprises an anchor compound having the general formula:

(R₁—O)_(V−n)MG_(n) where

-   -   M is germanium, hafnium, indium, silicon, tantalum, tin,        titanium, or tungsten;    -   G is a functional group capable of forming a chemical bond with        the metal;    -   R₁—O is a functional group capable of forming a chemical bond        with the oxide surface, O is oxygen;    -   V is the valence of M; and    -   n is an integer from 1 to V−1.        According to one embodiment of the present invention, R₁ is an        alkyl group, M is silicon, and G is an alkylamine. As an option        for one or more embodiments of the present invention, G        comprises amine, imine, epoxy, hydroxyl, carboxy, carboxylate,        phosphate, phosphonate, or combinations thereof. As an option        for one or more embodiments of the present invention, R₁— is an        alkyl group.

According to one or more embodiments of the present invention, theanchor compound in the solution comprises mono-alkoxy silane ordi-alkoxy silane and at least one from the group consisting of an aminegroup, an imine group, a carboxylate group, a cyanide group, a phosphategroup, a phosphite group, a phosphonate group, and an epoxy group.

According to one or more embodiments of the present invention, theanchor compounds have the formula presented above wherein G_(n)comprises groups such as, but not limited to, amine, imine, epoxy,hydroxyl, carboxy, carboxylate, phosphate, phosphonate, or combinationsthereof. According to one or more embodiments of the present invention,the anchor compounds have the formula presented above wherein G_(n)comprises, sulfonate, boronate, carbonate, bicarbonate, or combinationsthereof. According to one or more embodiments of the present invention,the anchor compounds have the formula presented above wherein(R₁—O)_(V−n) comprises methoxy, ethoxy, propoxy, or combinationsthereof. According to one or more embodiments of the present invention,the anchor compounds have the formula presented above wherein(R₁—O)_(V−n) comprises methoxy, ethoxy, propoxy, or combinations thereofand G comprises amine, imine, epoxy, hydroxyl, carboxy, carboxylate,phosphate, phosphonate, or combinations thereof.

According to one or more embodiments of the present invention, thesolution includes anchor compounds comprising an inorganic oxoanion, anamine, an imine, a cyanide, or combinations thereof. One or more otherembodiments of the present invention, the solution includes anchorcompounds having functional groups that can form complexes with ions ofthe metal used for the gapfill and/or functional groups that adsorbstrongly on the gapfill metal. For embodiments of the present inventionthat use cobalt in the gapfill metal, the solution comprises anchorcompounds having functional groups that can form complexes with ions ofcobalt and/or functional groups that adsorb strongly on cobalt.

According to one or more embodiments of the present invention, thesolution includes an anchor compound that comprises an inorganicoxoanion having the generic formula A_(X)O_(Y) ^(Z−) wherein, A is achemical element, O is oxygen, X is an integer, Y is an integer, and Zis an integer. Some examples of inorganic oxoanions for one or moreembodiments of the present invention include, but are not limited,phosphates and phosphites.

According to one or more embodiments of the present invention, thesolution comprises an amount of water-soluble solvent which is optional;an amount of anchor compound having at least one functional groupcapable of forming a chemical bond with the oxide surface and having atleast one functional group capable of forming a chemical bond with thegapfill metal; and an amount of water. According to one or moreembodiments of the present invention, the solution comprises a solventand an anchoring agent without a water soluble solvent. According to oneor more embodiments of the present invention the anchor compoundcomprises an inorganic oxoanion, such as but not limited to, aphosphate, a phosphite, an amine, an imine, a cyanide, and combinationsthereof or functional groups that can form complexes with metal ionsand/or adsorb strongly on the gapfill metal.

According to one embodiment of the present invention, the solutioncomprises an amount of anchor compound. In general, the anchor compoundhas at least one functional group capable of forming a chemical bondwith the oxide surface and has at least one functional group capable offorming a chemical bond with the gapfill metal. In another embodiment ofthe present invention, the solution comprises an amount of water-solublesolvent, an amount of anchor compound, and an amount of water.

The anchor compounds for embodiments of the present invention can havenumerous chemical compositions. There are many choices for the at leastone functional group capable of forming a chemical bond with the oxidesurface and for the at least one functional group capable of forming achemical bond with the metal. Some embodiments of the present inventionmay include anchor compounds having two or three or more functionalgroups capable of forming a chemical bond with the oxide surface.Similarly, some embodiments of the present invention may include anchorcompounds having two or three or more functional groups capable offorming a chemical bond with the gapfill metal. Optionally, anchorcompounds may be selected that include different types of functionalgroups capable of forming chemical bonds with the oxide surface. Anchorcompounds may be selected that include different types of functionalgroups capable of forming chemical bonds with the metal. Embodiments ofthe present invention may also use mixtures of different types of anchorcompounds.

According to one embodiment of the present invention, the anchorcompound includes an alkoxysilane such as a mono-alkoxy silane, such asa di-alkoxy silane, and such as a tri-alkoxy silane for forming thechemical bond with the oxide surface. The anchor compound furtherincludes one or more polar groups such as, but not limited to, an aminegroup, an imine group, a carboxylate group, a phosphate group, aphosphonate group, and an epoxy group forming the chemical bond with thegapfill metal. As an option, anchor compounds according to someembodiments of the present invention may include dissimilar polar groupsor mixtures of dissimilar polar groups. For specific embodiments of thepresent invention, the type and amount of anchor compound is selected sothat the solution provides an effective amount of the anchor compound tothe oxide surface to accomplish increased bonding between the oxide andthe gapfill metal.

For another embodiment of the present invention, the solution includesan anchor compound having the general formula (R₁—O)_(V−n)MG_(n) where Mis germanium, hafnium, indium, silicon, tantalum, tin, titanium, ortungsten; G is the functional group capable of forming the chemical bondwith the gapfill metal; R₁—O is the functional group capable of formingthe chemical bond with the oxide surface, O is oxygen; V is the valenceof M; and n is an integer from 1 to V−1. One embodiment of the presentinvention has G comprising one or more polar groups such as, but notlimited to, amine, imine, epoxy, hydroxyl, carboxy, carboxylate,phosphate, phosphonate, sulfonate, boronate, carbonate, bicarbonate, orcombinations thereof. Preferably, R₁ is an organic group such as analkyl group and R₁—O is an alkoxy group such as methoxy, ethoxy, andpropoxy. For another embodiment of the present invention, (R₁—O)_(V−n)includes one or more groups such as, but not limited to, methoxy,ethoxy, propoxy, and combinations thereof and G_(n) comprises one ormore groups such as, but not limited to, amine, imine, epoxy, hydroxyl,carboxy, carboxylate, phosphate, phosphonate, and combinations thereof.In another preferred embodiment, R₁ is an alkyl group, M is silicon, andG is an alkylamine.

Another embodiment of the present invention is a solution comprisingcomponents for electroless deposition and an anchor compound. Thecomponents for electroless deposition may comprise, but are not limitedto, a solvent, a reducing agent for electroless deposition, and ionsand/or complexes of one or more metals for electroless deposition of agapfill metal. Descriptions of typical electroless deposition solutionsand components of electroless deposition solutions can be found incommonly only owned patents U.S. Pat. No. 6,794,288 to Kolics et al. andU.S. Pat. No. 6,911,076 to Kolics et al.; the contents of all of thesepatents are incorporated herein, in their entirety, by this reference.Descriptions of other electroless deposition solutions and components ofelectroless deposition solutions are also available elsewhere in thescientific and patent literature.

The anchor compound has at least one functional group capable of forminga chemical bond with an oxide surface and has at least one functionalgroup capable of forming a chemical bond with the gapfill metal. Detailsand examples of anchor compounds included in solution with componentsfor electroless deposition according to one or more embodiments of thepresent invention are presented above.

A solution, according to one embodiment of the present invention,comprises components for electroless deposition and an anchor compound.The anchor compound has the general formula (R₁—O)_(V−n)MG_(n) where

-   -   M is germanium, hafnium, indium, silicon, tantalum, tin,        titanium, or tungsten;    -   G is a functional group capable of forming the chemical bond        with the metal;    -   R₁—O is the functional group capable of forming the chemical        bond with the oxide surface, O is oxygen;    -   V is the valence of M; and    -   n is an integer from 1 to V−1.

A solution, according to one embodiment of the present invention,comprises components for electroless deposition and an anchor compound.The anchor compound comprises an inorganic oxoanion, a phosphate, aphosphite, a phosphonate, an amine, an imine, a cyanide, or combinationsthereof.

A solution, according to one embodiment of the present invention,comprises components for electroless deposition and an anchor compound.The anchor compound comprises inorganic oxoanions, amines, imines,cyanides, functional groups that form complexes with ions of the gapfillmetal, functional groups that adsorb strongly on the gapfill metal, orcombinations thereof.

A solution, according to one embodiment of the present invention,comprises components for electroless deposition and an anchor compound.The anchor compound comprises inorganic oxoanions having the generalformula A_(X)O_(Y) ^(Z−) wherein, A is a chemical element, O is oxygen,X is an integer, Y is an integer, and Z is an integer.

A solution, according to one embodiment of the present invention,comprises components for electroless deposition and an anchor compound.The anchor compound comprises mono-alkoxy silane, di-alkoxy silane, ortri-alkoxy silane and at least one member from the group consisting ofan amine group, an imine group, a carboxylate group, a phosphate group,a phosphonate group, and an epoxy group.

In the foregoing specification, the invention has been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the present invention as set forthin the claims below. Accordingly, the specification and figures are tobe regarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope of thepresent invention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any element(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature or element of any or all the claims.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having,” “at least one of,” or any other variationthereof, are intended to cover a non-exclusive inclusion. For example, aprocess, method, article, or apparatus that comprises a list of elementsis not necessarily limited only to those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

What is claimed is:
 1. A method of fabricating an electronic device, themethod comprising: providing a substrate having dielectric oxide surfaceareas adjacent to electrically conductive surface areas; chemicallybonding an anchor compound with the dielectric oxide surface areas so asto form an anchor layer; initiating the growth of a metal using theelectrically conductive surface areas and growing the metal so that theanchor layer bonds with the metal.
 2. The method of claim 1, wherein theanchor compound has at least one functional group capable of forming achemical bond with the oxide surface and having at least one functionalgroup capable of forming a chemical bond with the metal.
 3. The methodof claim 1, wherein the anchor compound comprises an inorganic oxoanion,an amine, an imine, a cyanide, a functional group that form complexeswith ions of the metal, a functional group that adsorbs strongly on themetal, or combinations thereof.
 4. The method of claim 1, wherein theanchor compound comprises an inorganic oxoanion having the genericformula A_(X)O_(Y) ^(Z−) wherein, A is a chemical element, O is oxygen,X is an integer, Y is an integer, and Z is an integer.
 5. The method ofclaim 1, wherein the anchor compound comprises phosphate, phosphite, orphosphonate.
 6. The method claim 1, wherein the anchor compoundcomprises mono-alkoxy silane, di-alkoxy silane, or tri-alkoxy silane andat least one from the group consisting of an amine group, an iminegroup, a carboxylate group, a cyanide group, a phosphate group, aphosphite group, a phosphonate group, and an epoxy group.
 7. The methodof claim 1, wherein the anchor compound has the general formula(R₁—O)_(V−n)MG_(n) where M is germanium, hafnium, indium, silicon,tantalum, tin, titanium, or tungsten; G is a functional group capable offorming the chemical bond with the metal; R₁—O is the functional groupcapable of forming the chemical bond with the oxide surface, O isoxygen; V is the valence of M; and n is an integer from 1 to V−1.
 8. Themethod of claim 7, wherein R₁ is an alkyl group, M is silicon, and G isan alkylamine.
 9. The method of claim 1, further comprising making thesurface of the metallization contacts substantially oxide free prior tothe chemically bonding an anchor compound with the dielectric oxide. 10.The method of claim 1, wherein the dielectric oxide is a surface oxideformed on a dissimilar material.
 11. The method of claim 1, wherein thechemically bonding an anchor compound with the dielectric oxide surfaceareas is a dry chemical process using a gas comprising the anchorcompound.
 12. The method of claim 1, wherein chemically bonding ananchor compound with the dielectric oxide surface areas is a wetchemical process using a liquid solution comprising the anchor compound.13. The method of claim 12, wherein the liquid solution furthercomprises dimethylsulfoxide, formamide, acetonitrile, alcohol, ormixtures thereof.
 14. The method of claim 1, wherein the oxide surfacecomprises at least one selected from the group consisting of SiO₂, SiOC,SiOCH, SiON, SiOCN, SiOCHN, Ta₂O₅, and TiO₂.
 15. The method of claim 1,wherein the gapfill metal comprises cobalt, copper, gold, iridium,nickel, osmium, palladium, platinum, rhenium, ruthenium, rhodium,silver, tin, zinc, electrolessly plated alloys, or mixtures thereof. 16.An electronic device fabricated using the method of claim
 1. 17. Anelectronic device comprising: a metallization contact; a dielectricoxide having a via and/or a trench to the metallization contact; agapfill metal grown from the metallization contact; and an anchor layerformed by an anchor compound chemically bonded between the dielectricoxide and the gapfill metal.
 18. The electronic device of claim 17,wherein the anchor layer comprises a chemical reaction product from areaction of the dielectric oxide and a reaction of the gapfill metalwith the anchor compound, the anchor compound comprises an inorganicoxoanion, an amine, an imine, a cyanide, or combinations thereof. 19.The electronic device of claim 17, wherein the anchor layer comprises achemical reaction product from a reaction of the dielectric oxide and areaction of the gapfill metal with the anchor compound, the anchorcompound comprises functional groups that can form complexes with ionsof the metal used for the gapfill metal and/or functional groups thatadsorb strongly on the gapfill metal.
 20. The electronic device of claim17, wherein the gapfill metal comprises cobalt, the anchor layercomprises a chemical reaction product from a reaction of the dielectricoxide and a reaction of the gapfill metal with the anchor compound, theanchor compound comprises functional groups that can form complexes withions of cobalt and/or functional groups that adsorb strongly on cobalt.21. The electronic device of claim 17, wherein the anchor layer is achemical reaction product from a reaction of the dielectric oxide and areaction of the gapfill metal with an anchor compound that comprises aninorganic oxoanion having the generic formula A_(X)O_(Y) ^(Z−) wherein,A is a chemical element, O is oxygen, X is an integer, Y is an integer,and Z is an integer.
 22. The electronic device of claim 17, wherein theanchor layer comprises a chemical reaction product from a reaction ofthe dielectric oxide and a reaction of the gapfill metal with the anchorcompound, the anchor compound having the general formula:(R₁—O)_(V−n)MG_(n) where M is germanium, hafnium, indium, silicon,tantalum, tin, titanium, or tungsten; G is a functional group capable offorming the chemical bond with the metal; R₁—O is the functional groupcapable of forming the chemical bond with the oxide surface, O isoxygen; V is the valence of M; and n is an integer from 1 to V−1. 23.The electronic device of claim 17, wherein the dielectric oxidecomprises at least one of Al₂O₃, SiO₂, SiOC, SiOCH, SiON, SiOCN, SiOCHN,Ta₂O₅, and TiO₂.
 24. The electronic device of claim 17, wherein thegapfill metal comprises at least one of copper, cobalt, nickel,tungsten, boron, phosphorus, and mixtures thereof.
 25. The electronicdevice of claim 22, wherein the anchor layer comprises O_(V−n)MG_(n) andG comprises amine, imine, epoxy, hydroxyl, carboxy, carboxylate,phosphate, phosphonate, or combinations thereof.
 26. A solution toincrease the bonding between an oxide surface and a gapfill metal, thesolution comprising: optionally, an amount of water-soluble solvent; anamount of anchor compound having at least one functional group capableof forming a chemical bond with the oxide surface and having at leastone functional group capable of forming a chemical bond with the gapfillmetal; and an amount of water.
 27. The solution of claim 26, wherein theanchor compound comprises an inorganic oxoanion, a phosphate, aphosphite, a phosphonate, an amine, an imine, a cyanide, or combinationsthereof.
 28. The solution of claim 26, wherein the anchor compoundcomprises inorganic oxoanions, amines, imines, cyanides, functionalgroups that form complexes with ions of the gapfill metal, functionalgroups that adsorb strongly on the gapfill metal, or combinationsthereof.
 29. The solution of claim 26, wherein the anchor compoundcomprises inorganic oxoanions having the generic formula A_(X)O_(Y)^(Z−) wherein, A is a chemical element, O is oxygen, X is an integer, Yis an integer, and Z is an integer.
 30. The solution of claim 26,wherein the anchor compound comprises phosphate, phosphonate, orphosphite.
 31. The solution of claim 26, wherein the anchor compound hasat least one functional group capable of forming a chemical bond withthe oxide surface and having at least one functional group capable offorming a chemical bond with the metal.
 32. The solution claim 26,wherein the anchor compound comprises mono-alkoxy silane, di-alkoxysilane, or tri-alkoxy silane and at least one member from the groupconsisting of an amine group, an imine group, a carboxylate group, aphosphate group, a phosphonate group, and an epoxy group.
 33. A solutioncomprising: a solvent; an anchor compound having at least one functionalgroup capable of forming a chemical bond with the oxide surface andhaving at least one functional group capable of forming a chemical bondwith the gapfill metal; a reducing agent for electroless deposition; andions of one or more metals for electroless deposition of a gapfillmetal.
 34. The method of claim 33, wherein the anchor compound has thegeneral formula(R₁—O)_(V−n)MG_(n) where M is germanium, hafnium, indium, silicon,tantalum, tin, titanium, or tungsten; G is a functional group capable offorming the chemical bond with the metal; R₁—O is the functional groupcapable of forming the chemical bond with the oxide surface, O isoxygen; V is the valence of M; and n is an integer from 1 to V−1. 35.The solution of claim 33, wherein the anchor compound comprises aninorganic oxoanion, a phosphate, a phosphite, a phosphonate, an amine,an imine, a cyanide, or combinations thereof.
 36. The solution of claim33, wherein the anchor compound comprises inorganic oxoanions, amines,imines, cyanides, functional groups that form complexes with ions of thegapfill metal, functional groups that adsorb strongly on the gapfillmetal, or combinations thereof.
 37. The solution of claim 33, whereinthe anchor compound comprises inorganic oxoanions having the genericformula A_(X)O_(Y) ^(Z−) wherein A is a chemical element, O is oxygen, Xis an integer, Y is an integer, and Z is an integer.
 38. The solutionclaim 33, wherein the anchor compound comprises mono-alkoxy silane,di-alkoxy silane, or tri-alkoxy silane and at least one member from thegroup consisting of an amine group, an imine group, a carboxylate group,a phosphate group, a phosphonate group, and an epoxy group.